yes there has been some years ago such things spread in the web, mostly with some kind of 'secret' around it, nobody ever found anything except some way to attack the service as result of some bugs in it.
The known bugs were then cleared with subsequent versions, otherwise nobody ever found any malware in the client or during operation of the service.
(there was found a spoiled copy on some of those fast-or-slow download servers some years ago, but this is not a surprise)

It did then work well for years, but unfortunately now it seems to be kind of abandoned, thought the servers work and the service works fine, comparatively fast but clearly not perfect known operation in terms of crypto or general security.

But still kind of useful in some countries with too much taking care about the 'health' of their citizens.